How to change the coordinate system of the control point?

Hi Guys, I am inserting some GCP in context capture, however, all the GCPs are in Hong Kong 1980 grid coordinates system but there's no such system in the pre-assigned coordinate system in ContextCapture.

May I know how can I change the coordinate system from WGS84 to local coordinate system (HK1980 grid system)?

Thank you so much!